Pressure intensifier

ABSTRACT

This disclosure relates to a hydraulic system incorporating a pressure intensifier which is a combination motor and pump and wherein the pressure intensifier has two discharge sources, one discharge source being a free discharge to a reservoir and the other discharge source being a high pressure discharge to a motor, the pressure intensifier being of the piston and cylinder type with the pistons being freely mounted within the cylinders and being associated with a cam so as to provide the required motor and pumping action.

United States Patent Inventor George M. Barrett R.R. 5, Gait, Ontario, Canada Appl. No. 819,154 Filed Apr. 25, 1969 Patented May 25, 1971 PRESSURE INTENSIFIER 3 Claims, 5 Drawing Figs.

US. Cl 60/52, 60/53, 91/491, 91/492, 92/58 int. Cl F151) 3/00, F15b 15/18 Field of Search 103/161, 49; 417/225; 91/202, 205; 60/545, 545 (HBHA), 53 (B); 92/58 [5 6] References Cited UNITED STATES PATENTS 2,454,418 11/1948 Zimmermann.. 60;103/97E;1

3,037,488 6/1962 Barrett 91/205 3,241,463 3/1966 Barrett 91/205 3,391,538 7/1968 Orloffet al 60/53B Primary ExaminerEdgar W. Geoghegan Attorney-Diner, Brown, Ramik and Holt W// 23 28 33 9 J 2 30 l 25 '5 4b 31 42 38 3| 51 4 '56 :44 mm 2 2 2 4 22 5'3 5? 1L l PRESSURE INTENSIFIER This invention relates in general to new and useful improvements in hydraulic systems and the components thereof, and more particularly to a hydraulic pressure intensifier.

This invention particularly relates to a pressure intensifier which may be incorporated in a circulating hydraulic system and which will, when driven by a source of hydraulic fluid under pressure, serve to recirculate a portion of the fluid under pressure at a pressure greater than the original pressure of the-fluid.

Another object of this invention is to provide a novel pressure intensifier for use in a circulating system the pressure intensifier having means for converting the energy of a large quantity of fluid at a predetermined pressure into a small quantity of the same fluid at a higher pressure and the remainder of the fluid into fluid at a lower pressure.

Another object of this invention is to provide a novel pressure intensifier for use in circulating hydraulic systems, the pressure intensifier being of the hydraulic motor type wherein reciprocating pistons are actuated by hydraulic fluid under pressure, and the same pistons on their return strokes, serve to pump at least a portion of the actuating hydraulic fluid at a pressure greater than the pressure of the hydraulic fluid when admitted to the pressure intensifier.

A still further object of this invention is to provide a novel pressure intensifier for hydraulic systems, the pressure intensifie'r including a hydraulic motor of the type having pistons freely mounted within cylinders formed in a rotor with the pistons being reactable upon a cam and the pistons on their return stroke serving to discharge hydraulic fluid from within the associated cylinders and with certain of the pistons functioning as pumping elements on their return strokes.

With the above, and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

FIG. 1 is a schematic view showing a hydraulic system incorporating a pressure intensifier formed in accordance with this invention.

FIG. 2 is a longitudinal vertical sectional view taken through the pressure intensifier and shows the specific details of construction thereof.

FIG. 3 is a transverse vertical sectional view taken along the line 3-3 of FIG. 2 and shows the specific porting of a portion of the pressure intensifier.

FIG. 4 is a transverse vertical sectional view similar to FIG. 3 and taken along the line 4-4 of FIG. 2.

FIG. 5 is a fragmentary sectional view similar to FIG. 3 and taken through a modified form of pressure intensifier.

Referring now to the drawing in detail, it will be seen that there is illustrated in FIG. 1 a hydraulic system which is generally referred to by the numeral 10. The hydraulic system includes a reservoir 11 to which a pump 12 is connected by means of a hydraulic line 13. The pump 12 is suitably driven and supplies hydraulic fluid under pressure through a hydraulic line 14 to a pressure intensifier which is generally referred to by the numeral 15. The pressure intensifier is formed in accordance with this invention, and the specific details thereof will be set forth hereinafter.

The construction of the pressure intensifier is such that a portion of the fluid supplied thereto through the hydraulic line 14 is returned to the reservoir 11 through a hydraulic line 16 at a relatively low pressure. A further line 17 extends from the pressure intensifier and hydraulic fluid under pressure is supplied to the line 17 by the pressure intensifier 15 at a pressure in excess of the pressure of the hydraulic fluid within the hydraulic line 14. The hydraulic line 17 is connected to a conventional hydraulic motor 18 which operates at a pressure higher than that supplied by the pump 12. A return line 19 connects the exhaust of the hydraulic motor 18 to the reservoir 11.

It will be readily apparent from the foregoing description of the hydraulic system 10 that all of the components thereof, with the exception of the pressure intensifier, are conventional. Accordingly, further description of the hydraulic system 10, with the exception of the pressure intensifier, is believed to be unnecessary.

Referring now to FIGS. 2, 3 and 4, in particular, it will be seen that there are illustrated the specific details of the pressure intensifier 15. Basically, the pressure intensifier 15 includes a housing 20 which has one end thereof closed by means of an end cap 21 which is secured to the housing 20 by means of a plurality of circumferentially spaced bolts 22.

The housing 20 is generally hollow and remote from the end cap 21, the housing 20 has a small diameter bore 23. Adjacent the end cap 21, the housing 20 has a large diameter bore 24. A shaft 25 has one end thereof seated in the small diameter bore 23 and projects into the large diameter bore 24. It is pointed out at this time that although the shaft 25 has been illustrated as being a separate part of the housing 20 for construction purposes, it may be an integral part.

A cam is seated within the bore 24, the cam being of a multiple lobe configuration, as is shown in FIGS. 3 and 4, and being referred to by the numeral 26. It is to be noted that the cam 26 is locked in a preset position by means of at least one pin 27 extending between the cam 26 and the end cap 21. It is also to be noted that the cam 26 serves to seal the joint between the housing 20 and the end cap 21. In addition, it is to be noted that the end cap 21 has a recess in the face thereof opposing the housing 20, the recess being referred to by the numeral 28 and being generally considered an extension of the bore 24.

A rotor 30 is mounted on the shaft 25 within the housing 24 and the recess 28 of the end cap 21. The rotor 30 is illustrated as having three rows of cylinders 31 with the cylinders of each row extending radially and entirely through the rotor 30 in the manner clearly shown in FIGS. 3 and 4. It is to be noted that the cam 26 has three lobes and there are eight cylinders 31 in each row of cylinders. However, the invention is not restricted to this particular combination in that numerous other combinations of cam lobes and cylinders may operate in the desired manner.

It is to be noted that there is a piston 32 mounted in each of the cylinders 31, and the pistons 32 bear against the cam 26. By providing proper fluid inlet and exhaust ports and by relating these ports to the configuration of the cam 26, it will be readily apparent that the rotor 30 may be rotated by means of fluid introduced into the inner ends of the cylinders 31 under pressure. A full discussion of the relationship of the rotor 30, the cylinders 31 and the pistons 32 and the cam 26 is found in my US Pat. No. 3,037,488, granted June 5, 1962.

In order to effect the operation of the pressure intensifier 15, the left end of the housing 20, as viewed in FIG. 2, is provided with an internally threaded bore 33 into which may be threaded an end component of the fluid line 14. An inlet passage 34 extends diagonally from the bore 33 into the interior of the housing 20 and opens into a diagonal passage portion 35 of an inlet passage 36 which is formed in the shaft25. The right-hand end of the inlet passage 36 is closed by means of a plug 37.

It is to be noted that the shaft 25 is formed with a longitudinally elongated inlet port 38 which is in direct communication with the inlet passage 36. It is to be noted that the port 38 will simultaneously deliver fluid to one cylinder 31 in each of the three rows of cylinders. The shaft 25 is provided with two other longitudinally extending inlet ports 39 and 40 which are disposed to opposite sides of the inlet port 38, as is clearly shown in FIGS. 3 and 4. As is shown in FIG. 3 by dotted lines, the inlet ports 39 and 40 are connected to the inlet passage 36 by means of passages 41 and 42, respectively.

In FIGS. 2 and 4, it is clearly shown thatthe shaft 25 is provided with three outlet ports 43 which are spaced 120 apart and which are staggered 60 with respect to the inlet ports. It is to be noted that the outlet ports 43 extend longitudinally and are positioned relative to the rotor 30 so as to be in communication with the two right-hand rows of cylinders 31. The outlet ports 43, which may be considered discharge ports, open through the right end of the shaft 25 into a collector chamber 44 formed in the end plate 21. The end plate 21 is provided with an internally threaded bore 45 which opens into the collector chamber 44 and in which may be threaded an end connection of the fluid line 16.

The shaft 25 is provided with a delivery passage 46 which extends inwardly from the left end of the shaft 25 and terminates generally in alignment with the left-hand row of cylinders 31. The left-hand end of the delivery passage 46 is closed by means of a plug 47. The shaft 25 has a delivery port 48 which directly communicates the delivery passage 46 with the rotating cylinders of the first row of cylinders at the bottom of the shaft 25. As is clearly shown in FIG. 3, the shaft 25 is provided with two outer delivery ports 50 which are disposed 120 on opposite sides of the delivery port 48. The delivery ports 50 are connected to the delivery passage 46 by means of suitable passages 51.

Fluid entering into the delivery passage 46 is delivered out of the housing 20 by means of a passage 52 formed in the housing 20. The passage 52 opens into an internally threaded bore 53 which received a terminal fitting of the fluid line 17.

OPERATION Fluid under pressure from the pump 12 is delivered into the pressure intensifier 15 through the fluid line 14. This fluid enters into the housing through the bore 33 and passes into the passage 34 and then into the passages 35 and 36. This fluid may be considered inlet fluid and as the rotor turns, the fluid is sequentially admitted to the inner ends of the cylinders 31 through the ports 38, 39 and 40. The fluid reacts on the pistons 32 and constantly urges these pistons outwardly. In turn, the pistons 32 react against the contoured surface of the cam 26 and efi'ect the rotation of the rotor 30 so that the rotor 30 is driven in the same manner as a rotor of a motor.

Considering only the two right-hand rows of cylinders, it will be seen that after the pistons 32 reach their outermost positions, as controlled by the shape of the cam 26, further rotation of the rotor 30 brings the respective cylinders into communication with the discharge ports 43 with the result that as the pistons are urged inwardly by the cam 26, the spent inlet fluid is exhausted out of the cylinders through the discharge ports 43 and out of the housing 20 through the bore 45 into the return line 16. The fluid being discharged out of the housing 20 through the bore 45 is at a very low pressure as compared to the pressure of the inlet fluid.

The inlet fluid disposed within the cylinders of the first row of cylinders is also urged inwardly by the inward movement of the pistons as the rotor 30 rotates. However, the inlet fluid within the cylinders of the first row of cylinders is not exhausted in the true sense of the word, but is pumped into the delivery passage 46 through the delivery ports 48 and 50. This delivered fluid has the flow thereof resisted by the motor 18 and as a result, there can be a pressure build up. Inasmuch as the fluid being delivered to the fluid line 17 is being pumped, and since the full capacity of the one row of cylinders from a pumping standpoint is only one third of the input capacity of the pressure intensifier 15, it will be readily apparent that the pressure of the fluid being discharged into the fluid line 17 may be greatly increased as compared to the pressure of the inlet fluid. Due to the fact that the motor action of the pressure intensifier 15 illustrated in the drawing is three times that of the pump action, it will be seen that from a theoretical standpoint the pressure of the delivery fluid can be three times that of the inlet fluid. This is not correct because of friction losses and slight leakage. However, the pressure of the delivery fluid will be approaching three times that of the inlet fluid.

In FIG. 5 there is illustrated a section through a modified form of pressure intensifier, the pressure intensifier being generally referred to by the numeral 60. The pressure intensifier will be of the same basic construction as the pressure intensifier 15. However, in lieu of having a rotor which is provided with three rows of cylinders, the pressure intensifier 60 has a rotor 61, which corresponds to the rotor 30, but has only one row of cylinders 62. In each of the cylinders 62, there is a piston 63 in the form of a ball, which piston rides against a cam 64 which is identical with the cam 26 except it is shorter in an axial direction.

The pressure intensifier 60 differs from the pressure intensifier 15 primarily in the details of a shaft 65 thereof which shaft corresponds to the shaft 25. The shaft 65 is provided with an inlet passage 66 which has an inlet port 67 in direct communication therewith and two other inlet ports 68 spaced 120 therefrom and connected thereto by means of passages 69. The shaft 65 also has formed therein two discharge ports 70 which correspond to the discharge ports 43 of the pressure intensifier 15 and which discharge ports 70- are connected together by a chamber (not shown) at the end of the shaft 65 in the same manner as are the discharge ports 43. The shaft 65 further has a delivery port 71 which is spaced from the discharge ports 70 and which opens into a discharge passage 72, the discharge passage 72 corresponding to the discharge passage 46 of the pressure intensifier 15.

OPERATION OF PRESSURE INTENSIFIER 60 The pressure intensifier 60, for all practical purposes, operates in the same manner as the pressure intensifier 15. Inlet fluid is delivered into the inlet passage 66 and passes into the cylinders 62 through the inlet ports 67 and 68. This causes the rotor 61 to rotate. As the cylinders 62 pass the discharge ports 70, the inlet fluid within the cylinders 62 freely passes therefrom and is exhausted out of the pressure intensifier 15 at a greatly reduced pressure as compared to the pressure of the inlet fluid. On the other hand, the inlet fluid trapped in the cylinders 62 as they approach the delivery port 71 is pumped from the cylinders 62 by the actions of the pistons 63 riding on the cam 64. The fluid being pumped from the cylinders 62 into the delivery port 71 is resisted through the connection of the pressure intensifier 60 to a suitable motor, such as the motor 18. As a result, there may be a buildup of pressure within the delivery passage 72. Theoretically, it is possible to obtain pressures approaching three times the pressure of the pressure of the inlet fluid.

At this time it is pointed out that although the pressure intensifier 60 has been illustrated as having a three lobe cam with three sets of inlet ports and three sets of ports which permit the flow of fluid from the cylinders, different numbers of lobes and ports may be utilized so as to provide for different multiplications of pressures. Also, it is to be understood that more than one of the ports receiving fluid from the cylinders may be delivery ports. For example, in the illustrated form of the pressure intensifier 60, one of the discharge ports 70 could be formed as a delivery port and connected to the delivery passage 72. The theoretical increase in pressure of such a pressure intensifier would be one and a half times that of the inlet pressure.

Although only preferred embodiments of the invention have been specifically illustrated and described herein, it is to be understood that minor variations may be made in the disclosed pressure intensifiers without departing from the spirit and scope of the invention.

1 claim:

1. A pressure intensifier for a hydraulic system comprising a housing, a tubular rotor rotatably journaled in said housing, said housing having a cam disposed coaxially and coextensive with said rotor, a plurality of radiating cylinders extending entirely through said rotor and opening towards both a fixed part of said housing and said cam, a free piston in each cylinder projecting from said rotor and riding on said cam, inlet port means in said housing fixed part for supplying a motivating fluid under pressure to all of said cylinders in timed sequence,

and discharge port means in said housing for receiving said motivating fluid during return strokes of said pistons, said discharge port means including a first passage for receiving a portion of the returning motivating fluid at a reduced pressure and a second passage for receiving the remainder of the returning motivating fluid at an increased pressure with certain of said pistons functioning as pressure pumping elements during return strokes thereof, all of said cylinders being arranged in a single row.

2. The pressure intensifier of claim 1 wherein said cam is a multiple lobe cam and said first and second passages are circumferentially spaced and in serial communication with all of said cylinders.

3. A hydraulic system comprising a reservoir, a pump, a pressure intensifier and a motor, said pressure intensifier including a housing, a tubular rotor rotatably journaled in said housing, said housing having a cam disposed coaxially and coextensive with said rotor, a plurality of radiating cylinders extending entirely through said rotor and opening towards both a fixed part of said housing and said cam, a free piston in each cylinder projecting from said rotor and riding on said cam, inlet port means in said housing fixed part for supplying a motivating fluid under pressure to all of said cylinders in timed sequence, discharge port means in said housing for receiving said motivating fluid during return strokes of said pistons, said discharge part means including a first passage for receiving a portion of the returning motivating fluid at a reduced pressure and a second passage for receiving the remainder of the returning motivating fluid at an increased pressure with certain of said pistons functioning as pressure pumping elements during return strokes thereof, all of said cylinders being arranged in a single row, said cylinders being arranged in axially spaced rows with said second passage being in serial communication with all of the cylinders of only certain of said rows and said first passage being in serial communication with all of the cylinders of the others of said rows, said pump being in communication with said reservoir and said inlet port means for supplying fluid under pressure to said inlet port means, said first passage being in direct communication with said reservoir with there being minimum back pressure on all of said pistons of said cylinders of the others of said rows, said second passage being in a communication with said motor for delivering fluid thereto at a greater pressure than that of the fluid supplied by said pump to said pressure intensifier, and said motor exhausting to said reservoir 

1. A pressure intensifier for a hydraulic system comprising a housing, a tubular rotor rotatably journaled in said housing, said housing having a cam disposed coaxially and coextensive with said rotor, a plurality of radiating cylinders extending entirely through said rotor and opening towards both a fixed part of said housing and said cam, a free piston in each cylinder projecting from said rotor and riding on said cam, inlet port means in said housing fixed part for supplying a motivating fluid under pressure to all of said cylinders in timed sequence, and discharge port means in said housing for receiving said motivating fluid during return strokes of said pistons, said discharge port means including a first passage for receiving a portion of the returning motivating fluid at a reduced pressure and a second passage for receiving the remainder of the returning motivating fluid at an increased pressure with certain of said pistons functioning as pressure pumping elements during return strokes thereof, all of said cylinders being arranged in a single row.
 2. The pressure intensifier of claim 1 wherein said cam is a multiple lobe cam and said first and second passages are circumferentially spaced and in serial communication with all of said cylinders.
 3. A hydraulic system comprising a reservoir, a pump, a pressure intensifier and a motor, said pressure intensifier including a housing, a tubular rotor rotatably journaled in said housing, said housing having a cam disposed coaxially and coextensive with said rotor, a plurality of radiating cylinders extending entirely through said rotor and opening towards both a fixed part of said housing and said cam, a free piston in each cylinder projecting from said rotor and riding on said cam, inlet port means in said housing fixed part for supplying a motivating fluid under pressure to all of said cylinders in timed sequence, discharge port means in said housing for receiving said motivating fluid during return strokes of said pistons, said discharge part means including a first passage for receiving a portion of the returning motivating fluid at a reduced pressure and a second passage for receiving the remainder of the returning motivating fluid at an increased pressure with certain of said pistons functioning as pressure pumping elements during return strokes thereof, all of said cylinders being arranged in a single row, said cylinders being arranged in axially spaced rows with said second passage being in serial communication with all of the cylinders of only certain of said rows and said first passage being in serial communication with all of the cylinders of the others of sAid rows, said pump being in communication with said reservoir and said inlet port means for supplying fluid under pressure to said inlet port means, said first passage being in direct communication with said reservoir with there being minimum back pressure on all of said pistons of said cylinders of the others of said rows, said second passage being in a communication with said motor for delivering fluid thereto at a greater pressure than that of the fluid supplied by said pump to said pressure intensifier, and said motor exhausting to said reservoir. 